BIOLOGY 1201 EXAM 3 FINAL PAPER
QUESTIONS AND SOLUTIONS
◉ Which of the following statements about mutations is false?
An addition mutation results in an added base in the DNA
sequence.
A deletion mutation results in the loss of a base in the DNA
sequence.
Addition and deletion mutations disrupt the primary structure of
proteins.
A knock-out mutation results in a total absence of the mutated
protein.
Answer: A knock-out mutation results in a total absence of the
mutated protein.
(A knock-out mutation refers to the loss of a protein's function but
not necessarily to its complete absence.)
◉ If a DNA sequence is altered from TAGCTGA to TAGTGA, what
kind of mutation has occurred?
,Both addition and deletion.
Addition.
Deletion.
None.
Answer: Deletion
The original sequence has lost the base C.
◉ Which mutation(s) would not change the remainder of the
reading frame of a gene sequence that follows the mutation(s)?
One addition mutation.
One addition and one deletion mutation.
One deletion mutation.
One addition and two deletion mutations.
Answer: One addition and one deletion mutation.
(This combination results in no net change in the number of
bases, so the reading frame would eventually be restored.)
◉ If the sequence ATGCATGTCAATTGA were mutated such that a
base were inserted after the first G and the third T were deleted,
how many amino acids would be changed in the mutant protein?
,Two.
One.
Three.
None.
Answer: 2
The second and third codons in the new sequence are different
from the original codons.
◉ If a mutated DNA sequence produces a protein that differs in
one central amino acid from the normal protein, which of the
following kinds of mutations could have occurred?
None.
An addition mutation
An addition mutation and a deletion mutation.
A deletion mutation.
Answer: An addition mutation and a deletion mutation
if the mutations occur within the same codon, only that codon
(amino acid) will be altered.
Return to Assignment
, ◉ During RNA processing a(n) _____ is added to the 5' end of the
RNA.
3' untranslated region
a long string of adenine nucleotides
5' untranslated region
coding segment
modified guanine nucleotide
Answer: modified guanine nucleotide
(The 5' cap consists of a modified guanine nucleotide.)
◉ During RNA processing a(n) _____ is added to the 3' end of the
RNA.
3' untranslated region
a long string of adenine nucleotides
5' untranslated region
coding segment
modified guanine nucleotide
Answer: a long string of adenine nucleotides
(A poly-A tail is added to the 3' end of the RNA.)
QUESTIONS AND SOLUTIONS
◉ Which of the following statements about mutations is false?
An addition mutation results in an added base in the DNA
sequence.
A deletion mutation results in the loss of a base in the DNA
sequence.
Addition and deletion mutations disrupt the primary structure of
proteins.
A knock-out mutation results in a total absence of the mutated
protein.
Answer: A knock-out mutation results in a total absence of the
mutated protein.
(A knock-out mutation refers to the loss of a protein's function but
not necessarily to its complete absence.)
◉ If a DNA sequence is altered from TAGCTGA to TAGTGA, what
kind of mutation has occurred?
,Both addition and deletion.
Addition.
Deletion.
None.
Answer: Deletion
The original sequence has lost the base C.
◉ Which mutation(s) would not change the remainder of the
reading frame of a gene sequence that follows the mutation(s)?
One addition mutation.
One addition and one deletion mutation.
One deletion mutation.
One addition and two deletion mutations.
Answer: One addition and one deletion mutation.
(This combination results in no net change in the number of
bases, so the reading frame would eventually be restored.)
◉ If the sequence ATGCATGTCAATTGA were mutated such that a
base were inserted after the first G and the third T were deleted,
how many amino acids would be changed in the mutant protein?
,Two.
One.
Three.
None.
Answer: 2
The second and third codons in the new sequence are different
from the original codons.
◉ If a mutated DNA sequence produces a protein that differs in
one central amino acid from the normal protein, which of the
following kinds of mutations could have occurred?
None.
An addition mutation
An addition mutation and a deletion mutation.
A deletion mutation.
Answer: An addition mutation and a deletion mutation
if the mutations occur within the same codon, only that codon
(amino acid) will be altered.
Return to Assignment
, ◉ During RNA processing a(n) _____ is added to the 5' end of the
RNA.
3' untranslated region
a long string of adenine nucleotides
5' untranslated region
coding segment
modified guanine nucleotide
Answer: modified guanine nucleotide
(The 5' cap consists of a modified guanine nucleotide.)
◉ During RNA processing a(n) _____ is added to the 3' end of the
RNA.
3' untranslated region
a long string of adenine nucleotides
5' untranslated region
coding segment
modified guanine nucleotide
Answer: a long string of adenine nucleotides
(A poly-A tail is added to the 3' end of the RNA.)
